SAP Message AA660 - Transaction in area & contradicts the net book value rule

Diagnosis
The document cannot be posted, as it is contrary to the net book valuerule which is checked in area &V1&.

Procedure
This error usually occurs when you enter proportional values. Theproportional values exceed the amount posted, for example, postcapitalization of 100 but proportional depreciation to the amount 110.Check your entries and correct them if necessary.